(CNN)Sure it's the Midwest, but every once in a while a storm comes along that tests the hardy folks of America's heartland.

Blizzard conditions slowly subsided across parts of Nebraska, Iowa, South Dakota and Minnesota overnight as the snow ended and the roaring winds began to calm.

The same storm system also slammed the South. Severe weather peppered the region at the end of an usually warm winter day.

But it was central and eastern Nebraska that took the brunt. Up to 20 inches of snow blanketed parts of the state, whipped by winds gusting to 50 mph.Road conditions were so bad, Interstate 80 was closed from Lincoln to North Platte, a stretch of more than 200 miles.

"Road closures in place for a reason. Don't be fooled!" the Nebraska State Patrol tweeted. "Blowing, drifting snow, reduced visibility Travel not advised."In Kansas, sections of 13 highways were closed and the other roads were icy and slippery, said Kim Qualls of the Department of Transportation.

In Minnesota, a snow emergency was declared in Minneapolis, according to the city's website.

Parking restrictions were in effect for 1,000 miles of road, the city said.The storm also grounded air travel across the region.

More than 700 flights were canceled on Tuesday and at least 250 more were called off for Wednesday, according to the flight-tracking website FlightAware.com.

Not every flight cancellation on the website is due to weather, but Denver, Omaha, Minneapolis-Saint Paul and Chicago reported the greatest number of cancellations.

Denver International Airport tweeted Tuesday morning: "About 125 canceled flights," and a number of flights were delayed up to an hour or more, according to flydenver.com. The airport said they have "500 trained employees and 250 pieces of equipment [to] help keep runways clear."Nasty weather also hammered the South, with tornado warnings issued in Mississippi and Alabama.

At least two tornadoes hit Mississippi, including in Shuqualak, the National Weather Service in Jackson said.

There were reports of damage in Collinsville to a church and several homes, said Dinah Farmer with the Lauderdale County Emergency Management.

The National Weather Service in Birmingham, Alabama, said a tornado cut through Pickens County on Tuesday evening. Sky Hallmon, an emergency official with the county, said several homes and mobile homes were damaged. Administrative offices for a federal prison also were damaged, he said.

Possible severe weather was forecast for northwest Georgia Wednesday morning.